DataSourceExample.swift

// basic example of using a DataSource class for a table view
// the data source will update itself every 2 seconds
// and then use the delegate / protocol pattern to tell
// the table view controller to update itsef

class SFDataSource: NSObject, UITableViewDataSource {

	weak var theUpdateDelegate: UpdateDelegate?
	
	private let reusableIdentifier:String
	
	private var theTimer: Timer!
	
	var myData = ["1", "2"]
	
	init(identifier reusableID:String, delegate: UpdateDelegate) {
		self.reusableIdentifier = reusableID
		self.theUpdateDelegate = delegate
		super.init()
		
		theTimer = Timer.scheduledTimer(timeInterval: 2, target: self, selector: #selector(runTimedCode), userInfo: nil, repeats: true)
		
	}
	
	@objc func runTimedCode() {
		let c = myData.count
		myData.append("\(c + 1)")
		theUpdateDelegate?.didUpdate()
	}
	
	func numberOfSections(in tableView: UITableView) -> Int {
		return 1
	}
	
	func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
		return myData.count
	}
	
	func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
		let cell = tableView.dequeueReusableCell(withIdentifier: reusableIdentifier, for: indexPath)
		cell.textLabel?.text = myData[indexPath.row]
		return cell
	}
	
}

protocol UpdateDelegate: class {
	func didUpdate()
}

class MyTableViewController: UITableViewController, UpdateDelegate {
	
	var reuseID = "myReuseID"
	
	var theDataSource: SFDataSource!
	
	func didUpdate() {
		DispatchQueue.main.async {
			self.tableView.reloadData()
		}
	}
	
	override func viewDidLoad() {
		super.viewDidLoad()
		
		// register a default table view cell
		tableView.register(UITableViewCell.self, forCellReuseIdentifier: reuseID)
		
		theDataSource = SFDataSource(identifier: reuseID, delegate: self)
		tableView.dataSource = theDataSource
		
	}
	
}